The Great Horned Owl is a species of owl known by the scientific name (Bubo virginianus) This powerful, graceful bird is the most common owl in the Americas and can be found in forests and meadows across the United States. Their strong wings, sharp talons, and excellent eyesight make them skilled hunters. They are nocturnal, and fly silently through the night sky. They mate for life, and are highly protective of their young. They are at the top of the food chain, and have very few enemies.[2] These birds of prey are known as "tigers of the sky"[3]

Contents

Anatomy

The talons of the Great Horned Owl

The Great Horned Owl is one of the largest owls. It can be easily identified by its prominent eartufts that are placed widely on its head.[4] The name "Great Horned" comes from these tufts of feathers. These ear tufts are called plumicorns, which resemble horns and cat-like ears. These plumicorns do not have anything to do with the owl's ability to hear. These owls vary from a gray to a reddish brown or black and white color. On their belly and chest, there is a white band of feathers with dark bars.[5] On their face, is a dark outline with a light brown center. The eyes of the owl are large, round, and gold. Their eyes cannot move, and in order to look up, down, or side to side they must move their whole head. They are able to turn their necks about 270 degrees. Sometimes they have white feathers under their chin. The Great Horned Owl is quite large with the males being 18-25 inches long and they have a wingspan reaching 35-60 inches. They have a wingspan that reaches 35-60 inches. The female great horned owl is usually larger than her mate and weighs approximately four and a half pounds, while the male weighs about three pounds.[6] This owl has sharp, black talons. Their enormous feet are covered with feathers all the way to the ends of their toes. At eight to twelve weeks, the young owls are almost fully feathered and begin to fly short distances.[7]

Reproduction

Great Horned Owls tend to mate for life. They begin the mating process at about two years old. The pair usually remains in the same territory for eight or more years. Nesting season is in January and February. The males and females hoot loudly and sing love songs to one another. The male has a deeper hooting voice than the female despite their smaller size. They drop their wings and bow to each other. They often rub their beaks together and preen each other's feathers. The female lays eggs, typically from one to five each year.[8] The males and females take turns sitting on the eggs and incubating them for 26 to 35 days. Great Horned Owls do not build their own nests. They either use the nest of a hawk, crow, or heron or they nest on cliffs, abandoned buildings, or in hollow trees. They tend to find a new nest each year because the babies are so active that they destroy the nest that they are currently using. The owls defend their nests aggressively, and will attack and kill any animal that attempts to invade their territory. The young owls roam away from the nest at the early age of six to seven weeks old.[9] These young owls are known as "branchers" because they spend their time on nearby branches until they are able to fly. Their parents feed them until they are about twelve weeks old. In the autumn, the fledglings leave home and travel as far as 150 miles away. At two years of age, the owls are fully mature and the breeding cycle begins once again. Great Horned Owls are solitary animals and only join up for mating season.[10]

Ecology

The distribution of the Great Horned Owls

The most common owl of the Americas, the Great Horned Owl, is found in almost all of the forested regions of North America, Central America and South America. They are found in the forests, meadows, deserts, swamps, and urban areas as well. They can also adapt in suburban areas and farmlands. The owls of the north migrate south in the winter, but the majority live year-round in warmer climates. They can be found in altitudes from sea level to as high as 12,000 feet. The Great Horned Owl tends to have a limited range for hunting of about eight to ten kilometers.[11] These owls are excellent nocturnal hunters. Most of the time they perch high in a tree and fly down to attack their victims. Since they fly very quietly, their prey cannot usually hear them coming. Since they have excellent hearing, they are able to determine the exact location of their prey just by listening. Their diet consists of a variety of small and medium birds, reptiles, mammals, fish, amphibians, and insects. Great Horned Owls have two dangerous enemies, other Great Horned Owls and man. Occasionally, they have been known to attack a person who is getting too close to their nest. Much damage is done to the skin when an owl strikes a man with its sharp, powerful talons. These owls are sometimes attacked by large hawks, but the owl usually wins the fight.[12]

Hunting

Great Horned Owls are excellent hunters. They hunt by either perching in trees or flying in slow motion high above the ground. When they sight prey, they fold their wings and dive down for their kill. When grasped by the owl's talon the animal is usually instantly killed. Great Horned Owls hunt mostly at night, therefore they are considered nocturnal. In the wintertime they sometimes hunt during the daylight hours. This animal is known as "the tiger of the sky" because it is fierce and can capture prey that is larger and heavier than it's self.[13] This owl has great night vision and hearing. It approaches silently and attacks its prey often before it is noticed. It is quick and its sharp talons are excellent weapons.[14] Sometimes they hunt for smaller prey by standing or walking on the ground. Usually the Great Horned Owl eats small or medium sized rodents such as mice, rabbits, shrews, or squirrels. They are known to eat an occasional bat, raccoon, housecat, or domestic dog. They eat skunks regularly, and may be one of the only animals to do so. When you smell this owl, he or she often smells like a skunk. Farmers have indicated that these owls have enjoyed eating chickens and ducks from their farmyards. These owls have a very strong digestive system. Most times they swallow their prey whole. Then they regurgitate pellets that have compacted and formed in their stomachs. These pellets consist of fur, bones, teeth, and other parts of the animal that are not digestible. One or more of these pellets are regurgitated daily. Scientists can tell by examining these pellets what the owl has recently eaten.[15] The Great Horned Owl provides much of the food that it hunts to its growing fledglings.

Gallery

Great Horned Owl (B. virginianus)

Great Horned Owl (B. virginianus)

Great Horned Owl (B. virginianus)

Great Horned Owl (B. virginianus)

References

All About Birds D.G. Smith and C. Rhonor, The Birds of North America inc, accessed 1-25-11